Schaap, 54, admitted to adultery and "improper behavior" with the teenager, leading a board of deacons to fire him last month, a church spokesman said at the time.

Schaap had a relationship between June 1 and July 30 with a girl who had not yet turned 18, and took her from Indiana to Illinois and to Michigan, according to the criminal information. Schaap took the girl "with the intent that she engage in sexual activity for which (Schaap could) be charged with a criminal offense," according to the information.

Prosecutors are seeking the forfeiture of several items Schaap is alleged to have used in committing the crime, including an iPad, an iPhone, a digital camera, a voice recorder and two computer flash drives, according to the information.

In his plea agreement, which also was filed in federal court today, Schaap admits that he had sex with the girl, the girl was under his care or supervision, and he used a computer to persuade the girl to have sex with him illegally.

Schaap was scheduled to have his initial court appearance Wednesday at 3 p.m. before U.S. Magistrate Judge Paul Cherry in Hammond. As part of the plea deal, he waived his right to have the charges against him considered by a grand jury for indictment.

An FBI spokesman said last month that the agency was investigating whether Schaap was involved in “an improper sexual relationship with an underage.”